"Frankly, Walter," he said, as we walked along, "I don't know what to think. You know even the greatest experts sometimes disagree over questions like this. Well, Walter, art is long and time is fleeting. If we are ever to settle where that real Watteau is, we shall have to resort to science, I think."

That afternoon after a trip up to the laboratory, where Craig secured a peculiar and cumbersome photographic outfit, we at last found ourselves around at Faber's private gallery. Faber was out, but, true to his promise, he had left word with his man, who admitted us.

Kennedy set to work immediately, before the painting, placing an instrument which certainly was not like a regular camera. I was further astonished, moreover, when Craig set up something back of the canvas, which he moved away from the wall. As nearly as I could make it out it consisted of a glass bulb of curious shape. A moment later he attached the bulb to a wire that connected with a little rheostat or resistance coil and thence, in turn, to an electric-light socket.

He switched on the electric current and the apparatus behind the picture began to sputter. I could not see very well what it was, but it looked as if the bulb was suffused with a peculiar, yellowish-green light, divided into two hemispheres of different shades. The pungent odor of ozone from the electric discharge filled the room.

While Kennedy was working, I had noticed a little leather party box lying on a table, as though it had been forgotten. It was not just the thing one would expect in Faber's rooms and I looked at it more closely. On it were the initials "R. T." Had Rita Tourville visited him?

Craig had scarcely finished and was packing up his apparatus when we heard a noise outside. A second later, Faber himself entered, with Rita, evidently looking for something.

"Oh, yes, Rita,—here it is. Why, Kennedy—how are you? Did you get your photograph?"

Kennedy replied that he had, and thanked him.

It was easy to see Rita's pleasure at being with the young connoisseur, but at the sight of Craig I fancied for a moment that I saw a flash of that passionate resentment which had caused me to find a resemblance between the expression of her face and that of De Montespan in the painting, a hint at what she would do or dare to protect the object of her affections.

We departed shortly, leaving Rita and Faber deep in the discussion of some art topic.